Recently, DVDs (Digital Versatile Discs), BD (Blu-ray Discs (registered trademark)), or the like are widely used as information recording media (media) of various contents such as movies or music. Many of the contents such as music data and image data recorded in these information recording media are copyrighted or distribution-righted by creator or sellers thereof. Therefore, even the users who have purchased the disc, usage of the disc-recorded contents are limited to a certain extent. For example, copying a disc-recorded content to media such as other discs unlimitedly is not allowed.
Examples of a copy management configuration of the media-recorded contents as described above include a configuration of copy authorization process subject to reception of copy authorization information from a management server. More specifically, the process is performed in the following sequence.
A user loads a medium such as a content-stored disc in a user's apparatus such as a PC or a recording and reproducing apparatus, and the user's apparatus is connected to a management server via a network. Subsequently, the user's apparatus transmits prescribed information such as disc identifier (ID) to the server. The server verifies the validity or the like of the received information, and transmits copy authorization information to the user's apparatus. The user's apparatus is configured to be allowed to start a copying process under the condition of reception of the copy authorization information from the server.
Such a copy management configuration is referred to as Managed Copy (MC) and is disclosed in detail in Patent Document 1 (JP-A-2008-98765), for example.
In contrast, as a standard relating to a copyright protecting technology of the contents, there is an AACS (Advanced Access Content System) standard. Many of the disc-recorded contents such as the BD complying with an AACS standard are recorded as encrypted contents. Examples of the representative encryption configuration of the AACS standard include a configuration in which the content is segmentalized into units and different encryption keys are applied thereto. By employing such the encryption configuration, content usage control on a unit to unit basis is enabled and strict and a huge variety of content usage controls are realized.
The units, which are divided units of the content are referred to as “CPS units”, and encryption keys applied to an encryption process or a decoding process of the respective CPS units are referred to as CPS unit keys, unit keys, or title keys.
As regards the AACS standard, Non-patent document 1 (http://www.aacsla.com/home) or Non-patent document 2 (http://www.aacsla.com/specifications), and the like may be referenced.
When reading out the encrypted content applied with encryption keys different from one unit to another from a disc and copying the same to media such as other discs, a process of decoding the encrypted content to be copied once, and then, performing re-encryption of the decoded content complying with the standard of the management system corresponding to the media as copying destinations and recording the same is performed in many cases. In other words, the medium as a copying destination is also recorded as a usage controlled content.
In this case, if the content management system of the copy source (referred to as a first management system) and the content management system of the copy destination (referred to as a second management system) are different, processes of decoding the encrypted content of the copy source once and performing a process according to the content management system of the copy destination (second management system), for example, re-encryption using another encryption key for recording are required.
In this manner, a content copying process is required to be performed in a sequence of:
(1) reading out the encrypted content from a first medium (copy source medium);
(2) a decoding process for the encrypted content complying with the first management system compatible with the first medium (copy source medium);
(3) an encryption process for the content complying with the second management system compatible with the second medium (copy destination medium); and
(4) a recording process for the encrypted content with respect to the second medium (copy destination medium).
If the recorded content in the first medium (copy source medium) is an encrypted content on a unit to unit basis as described above, performing processes of specifying the configuration units of the content, acquiring the unit keys corresponding to the specified respective units in sequence, and performing a decoding process for each of the units is required.
When the copying process is performed under the copy management on the condition that the copy authorization information is received from the above-described server, the user's apparatus needs to perform decoding by applying the unit keys on a unit to unit basis. However, there is no effective prescription for the user's apparatus to acquire information for specifying the unit. Therefore, there is a problem that the copying process for the encrypted content on a unit to unit basis cannot be executed smoothly.
Also, there are a variety of contents to be copied such as a reproduction-pass-specific content which sets a reproduction pass corresponding to the information processing apparatus and causes the apparatus to execute reproduction according to the reproduction pass.
Alternatively, there is a content-code-applied content which allows a reproduction process only after having validated a reproduction sequence to be executed in the reproducing apparatus and executed a check by applying a code (content code) for validating whether or not the reproduction process is executed according to a correct reproducing procedure.
The reproduction-pass-specific content is described in Patent Document 2 (JP-A-2008-84445), and the content-code-applied content is described in Patent Document 3 (Japanese Patent No. 4140624).
When performing a copying process for various types of contents as described above, there is a problem that a normal copying process cannot be performed if the processes adapted to the respective content types are not performed.